1. Field of the Invention
The invention relates to a capacitance sensing mechanism, and more particularly to a programmable band-pass filter circuit of an analog front-end circuit applied for capacitance sensing/detection.
2. Description of the Prior Art
Generally speaking, a conventional capacitance sensing mechanism is arranged to adopt a programmable gain amplifier and an anti-aliasing filter to perform the operation of converting the capacitance of a sensed capacitor into a voltage value and perform the operation of anti-aliasing, respectively. This, however, inevitably causes high circuit costs. In addition, the conventional capacitance sensing mechanism may introduce the smearing effect which causes that the capacitances of non-touched cell(s) are increased due to adjacent touched cell (s), and thus the conventional capacitance sensing mechanism may generate a false sensing result.